The invention relates to a lathe comprising a machine frame, at least one workpiece spindle arranged on the machine frame and rotatable about a spindle axis, two tool carrier systems movable relative to the machine frame in a Z direction parallel to the spindle axis and comprising tool carriers for several tools, each of these tool carrier systems being guided independently of the other respective tool carrier system so as to be movable with its own slide system in the Z direction on the machine frame.
Lathes of this type are known from the state of the art, wherein these lathes are either not suitable for the machining of shafts with two tool carrier systems and or the two tool carrier systems cannot be used at the same time in an optimum manner.
The object underlying the invention is therefore to improve a lathe of the type described at the outset in such a manner that machining of a shaft with optimum use of two tool carrier systems is possible.
This object is accomplished in accordance with the invention, in a lathe of the type described at the outset, in that the tool carrier systems are arranged on the same side of the spindle axis and each tool carrier system is thereby movable in the Z direction on a path which extends to the other tool carrier system in a collision-prone manner and that each tool carrier system has a tool carrier head which can be positioned in a first position in relation to the respective slide system such that this represents the structural component of the respective tool carrier system located closest to the other tool carrier system.
With the inventive solution, the possibility is thus created, by way of the advantageous possibility of the arrangement of the tool carrier head in the first position, of being able to use the tool carrier heads in an optimum manner since they can essentially be moved towards one another until immediately prior to a collision and thus the tools can be used close to one another and so an optimum operating area is available for each tool carrier system.
Alternatively or in addition to the inventive solution described at the outset, one particularly advantageous embodiment provides for the tool carrier systems to be arranged on the same side of the spindle axis and each tool carrier system to thereby be movable in the Z direction on a path which extends to the other tool carrier system in a collision-prone manner, and for each slide system to have an X slide which is guided on the Z slide and is arranged on a side of the Z slide facing the other tool carrier system.
A particularly favorable arrangement of the X slide provides for a guide plane, in which the X guide means for the movement of the X slide relative to the Z slide are located, to be located on a side, which faces the respectively other tool carrier system, of a guide element of the Z slide located closest to the respectively other tool carrier system.
With this solution it is ensured that the guide plane for the X slide is displaced to such an extent in the direction of the respectively other tool carrier system that the X guide means can be brought as close as possible to the Z guide means without hindrance by the guide elements of the Z slide in order to achieve as stable a guidance of the tools as possible by means of the X slide and the Z slide relative to the machine frame which ensures as great a precision of the machining as possible.
In this respect, it is particularly favorable when the X slide of each of the slide systems extends beyond a Z slide guiding this X slide in the direction of the respectively other tool carrier system.
A particularly favorable development of the slide systems provides for the Z slide to have X guide means which are arranged on a slide member thereof in such a manner that they are located closer to the respectively other tool carrier system than the respective slide member.
With respect to the position of the guide plane determined by the X guide means, no further details have so far been given.
It is particularly favorable, for example, for as stable a guidance of the X slide as possible relative to the Z slide when the guide plane determined by the X guide means extends transversely to the spindle axis since sufficient space for a stable design of the guide means is available transversely to the spindle axis without any restriction of the path of action of the tool carrier systems in Z direction resulting from this.
With respect to the definition of the movability of the tool carrier systems in Z direction on a collision-prone path it would, for example, be conceivable not to have the slide systems movable on a collision-prone path but merely the tool carriers. Since collisions of the tool carriers have to be taken into consideration in any case, it is, with a view to a particularly stable guidance of both tool carriers, constructionally favorable when the slide systems of both tool carrier systems can be moved in the Z direction on a collision-prone path. The simplest possibility for realizing this provides for the slide systems to be movable in Z direction on the same guide paths.
In order to be able to position the tools as close to one another as possible, it is preferably provided for the tool carrier heads to be aligned in the first position in such a manner that their tool receiving means allow use of tools which extend in an area extending transversely to the spindle axis at a point of intersection with the spindle axis.
As a result of the fact that tools can be used which are located in an area which extends at the point of intersection with the spindle axis transversely thereto, it is possible to travel with the tool carriers of the different tool carrier systems as close as possible towards one another and thus to operate lying as near as possible to one another during turning of the shaft.
In this respect it is particularly expedient when the areas extending transversely to the spindle axis extend approximately parallel to one another at the point of intersection with the spindle axis.
In order to be able to equip the tool carrier heads with tools as favorably as possible, it is preferably provided for the tool carrier head to be arranged in the first position relative to the slide system supporting it in such a manner that the slide system forms a free space for the tools extending away from the tool carrier head approximately in directions transverse to the spindle axis. This applies for at least one of the tool carriers of the tool carrier systems.
Both tool carriers of the tool carrier systems are preferably arranged in the first position in such a manner.
This may be realized particularly favorably when the tool carrier head can be positioned in the first position relative to the slide system supporting it in such a manner that this projects beyond a side surface of the slide system located closest to the respectively other tool carrier system in the direction of the other tool carrier system.
In order to be able to carry out not only shaft machinings but also other machinings with the inventive lathe, it is preferably provided for a counterspindle to be provided so as to be located opposite the spindle so that each of the tool carrier systems can cooperate with one of the spindles for the machining of a workpiece.
In order to be able to carry out, in particular, machining on front and rear sides, it is preferably provided for the spindle and the counterspindle to be movable towards one another for the transfer of workpieces.
In principle, it is possible with the inventive solution to also carry out machining of the workpieces in the spindle and the counterspindle with one of the respective tool carrier systems with a tool carrier head located in the first position.
For this purpose, tools are preferably used which extend in areas transverse to the spindle axis or to both spindle axes.
In order, however, to be able to carry out machinings, in particular, on the end side of the workpieces and of recesses extending into the end side, it is necessary to also use tools which extend approximately parallel to the spindle axis.
For this purpose, it is particularly favorable when at least one of the tool carrier heads is located in a second position relative to the slide system supporting it on a side of the tool carrier facing away from the other tool carrier system. In this second position, tools which extend parallel to the spindle axis may be used in the tool carrier head particularly favorably.
For this purpose, it is, in particular, favorable when, in the area of the tool carrier head in the second position, the slide system forms a free space for tools extending approximately in the direction of the spindle axis, these tools then being able to extend in the opposite direction to the respectively other tool carrier system proceeding from the respective tool carrier head without collisions of these tools in the two tool carrier systems with one another needing to be feared.
In this respect, it is particularly favorable when the tool carrier head is located in the second position in front of a side of the slide system facing towards the side of the corresponding spindle.
In order to be able to move the tool carrier head from the first position into the second position, the most varied of solutions are conceivable. One particularly favorable solution, for example, provides for the respective tool carrier to be movable relative to the X slide in such a manner that the tool carrier head can be brought from the first position into the second position, i.e. the transfer of the tool carrier head between the first position and the second position is brought about by way of a relative movement of the tool carrier with respect to the X slide.
Such a movement may be realized in a particularly simple manner when the tool carrier head can be moved from the first position into the second position by way of a pivoting movement.
A particularly favorable solution from a constructional point of view provides for the tool carrier to be mounted on the X slide so as to be pivotable about an axis. Such an axis is preferably an axis extending transversely to the spindle axis.
A particularly preferred solution provides for this axis to extend at right angles to the spindle axis and represent a so-called B axis of the machine tool.
The tool carrier can, in principle, be of any optional design as long as it creates the possibility of bringing several tools into use. Such a tool carrier could, for example, in the simplest case be a so-called linear tool carrier.
A particularly favorable form of a tool carrier provides for the tool carrier to be designed as a tool turret.
In this respect, it is particularly favorable when the tool turret has a turret head which is arranged on one side of a turret housing.
Such a turret head is preferably pivotable about a turret axis in relation to the turret housing.
This turret axis is preferably located such that the turret head is pivotable in relation to the turret housing about a turret axis which extends transversely to an X axis of the machine tool.
In this respect, the turret axis could take up any optional number of positions about the X axis. The turret axis is located particularly favorably when it extends approximately parallel to the Z axis.
With respect to the pivotability of the turret head into the first and the second positions, it is preferably provided for the turret housing to be pivotable about a pivot axis in relation to the X slide.
In this respect, the pivot axis is preferably aligned such that it extends transversely to the Z axis. In this respect, the turret head can preferably be brought from the first position facing the other tool carrier system into the second position facing away from the other tool carrier system by way of pivoting of the turret housing about the pivot axis.
Additional features and advantages of the invention are the subject matter of the following description as well as the drawings illustrating one embodiment.